2.2.1 The three states of matter
Properties of Solids, Liquids and Gases
Solid | Liquid | Gas |
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State Changes
States of matter can be represented using a model called particle theory.
How are particles represented in this model? (1)
Small solid spheres
Explain the limitations of particle theory (2)
- Doesn’t show forces between particles
- Particles are not solid spheres
- Particle theory can be used to explain changes of state.
- Using particle theory, explain how a substance changes from a liquid to a gas when it is heated. (3)
- When a liquid is heated, particles gain KE & move faster
- Weakens bonds holding liquid tgt
- At certain temp, particles have sufficient energy to break bonds
- Liquid becomes gas
- 2.2.2 State symbols
Solid (s), Liquid (l), Gas (g), Aqueous solution (aq) - 2.2.3 Properties of ionic compounds
(See 2.1.2 Ionic bonding)
2.2.4 Properties of small molecules
(See 2.1.4 Covalent bonding)
- Long chain molecule made from joining many short molecules (monomers) together
- Strong intermolecular force – hard to break – solid at room temp
- Different polymers, different properties, different uses
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Thermosoftening polymer Thermosetting polymer - Contain long polymer chains
- Chains are not joined tgt (but are tangled up with each other)
- Low melting point – soften and then melt when heated
- Contain long polymer chains
- Chains are joined by covalent bonds
- High melting point – do not soften or melt when heated
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2.2.6 Giant covalent structures
(See 2.1.4 Covalent bonding)
2.2.7 Properties of metals and alloys
(See 2.1.5 Metallic bonding)
2.2.8 Metals as conductors
(See 2.1.5 Metallic bonding)